Minimally invasive apparatus for internal ablation of turbinates

ABSTRACT

A method and apparatus for ablating at least a portion of a nasal concha. The apparatus includes a catheter having a distal portion with a dimension configured for positioning through a nostril of a patient into a nasal meatus adjacent a nasal concha, and an energy delivery device coupled to the catheter distal portion including one or more energy delivering probes extendable from the catheter distal portion a sufficient distance to be inserted into an interior of the nasal concha to deliver ablative energy therein. The distal portion of the apparatus may also include an expandable member, expansion of the expandable member within the nasal meatus immobilizing the distal portion within the nasal meatus.

RELATIONSHIP TO COPENDING APPLICATIONS

This application is a continuation-in-part of application Ser. No.08/754,588, "Method for Ablating Turbinates", filed Oct. 19, 1996;application Ser. No. 08/753,063, "Apparatus for Ablating Turbinates",filed Oct. 19, 1996 and application Ser. No. 08/752,076, "NoninvasiveApparatus for Ablating Turbinates", filed Oct. 19, 1996 all of which arecontinuation-in-part applications of application Ser. No. 08/651,796,"Method and Apparatus for Ablating Turbinates" filed May 22, 1996 and ofapplication Ser. No. 08/651,798, "Method and Apparatus for AblatingTurbinates", filed May 22, 1996; all of which are a continuation-in-partof application Ser. No. 08/265,459, now U.S. Pat. No. 5,505,730. "ThinLayer Ablation Apparatus", filed Jun. 24, 1994, all of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a method and apparatus for treatingairway obstructions. More specifically, the present invention relates toa method and apparatus for reducing the volume of turbinates in a nasalpassageway in order reduce nasal airway obstructions.

BACKGROUND OF THE INVENTION

Sleep-apnea syndrome is a medical condition characterized by daytimehypersomnomulence, morning arm aches, intellectual deterioration,cardiac arrhythmias, snoring and thrashing during sleep. It is caused byfrequent episodes of apnea during the patient's sleep. The syndrome isclassically subdivided into two types. One type, termed "central sleepapnea syndrome", is characterized by repeated loss of respiratoryeffort. The second type, termed obstructive sleep apnea syndrome, ischaracterized by repeated apneic episodes during sleep resulting fromobstruction of the patient's upper airway or that portion of thepatient's respiratory tract which is cephalad to, and does not include,the larynx.

Treatments for sleep apnea thus far include various medical, surgicaland physical measures to unobstruct the airways. Medical measuresinclude the use of medications such as protriptyline,medroxyprogesterone, acetazolamide, theophylline, nicotine and othermedications in addition to avoidance of central nervous systemdepressants such as sedatives or alcohol. The above medical measures aresometimes helpful but are rarely completely effective. Further, themedications frequently have undesirable side effects.

Surgical interventions have included uvulopalatopharyngoplasty,tonsillectomy, surgery to correct severe retrognathia and tracheostomy.Other surgical procedures include pulling the tongue as forward aspossible and surgically cutting and removing sections of the tongue andother structures which can close off the upper airway passage. Theseprocedures may be effective but the risk of surgery in these patientscan be prohibitive and the procedures are often unacceptable to thepatients.

Among the air passageways in the body that can become obstructed are thenasal passageways leading from the nose to the pharynx. There are threenasal passageways, namely the inferior, middle and superior nasalmeatus. The turbinates, also referred to as nasal concha, are a seriesof tissues which form at least a portion of these nasal passageways.Forming a portion of the inferior nasal meatus is the inferior nasalconcha. The inferior and middle nasal concha each form a portion of themiddle nasal meatus. The middle and superior nasal concha each form aportion of the superior nasal meatus. When the inferior, middle and/orsuperior nasal concha become enlarged, the various nasal meatus whichallow air to pass through the nose into the pharynx can becomeobstructed.

Opening of obstructed nasal airways by reducing the size of theturbinates has been performed using surgical and pharmaceuticaltreatments. Examples of surgical procedures include anterior andposterior ethmoidectomy, such as those described in "EndoscopicParanasal Sinus Surgery" by D. Rice and S. Schaefer, Raven Press, 1988);the writings of M. E. Wigand, Messerklinger and Stamberger; and U.S.Pat. No. 5,094,233. For example, as described in U.S. Pat. No.5,094,233, the Wigand procedure involves the transection of the middleturbinate, beginning with the posterior aspect, visualization of thesphenoid ostium and opening of the posterior ethmoid cells forsubsequent surgery. In the sphenoidectomy step, the ostium of thesphenoid is identified and the anterior wall of the sinus removed.Following this step, the posterior ethmoid cells may be entered at theirjunction with the sphenoid and the fovea ethmoidalis can be identifiedas an anatomical landmark for further dissection. In anteriorethmoidectomy, the exenteration of the ethmoids is carried anteriorly tothe frontal recess. Complications, such as hemorrhage, infection,perforation of the fovea ethmoidalis or lamina papyracea, and scarringor adhesion of the middle turbinate, are reported in connection withthese procedures.

One of the problems encountered as a result of these procedures ispostoperative adhesion occurring between the turbinates and adjacentnasal areas, such as medial adhesion to the septum and lateral adhesionto the lateral nasal wall in the area of the ethmoid sinuses. Otherwisesuccessful surgical procedures may have poor results in these cases.Some surgeons have proposed amputation of a portion of the turbinate atthe conclusion of surgery to avoid this complication, resulting inprotracted morbidity (crust formation and nasal hygiene problems). Theturbinate adhesion problem detracts from these endoscopic surgicalprocedures. Efforts have been made to reduce the complicationsassociated with the surgical treatment of turbinate tissue, for exampleby the use of a turbinate sheath device. U.S. Pat. No. 5,094,233.

U.S. Pat. No. 3,901,241 teaches a cryosurgical instrument which is saidto be useful for shrinking nasal turbinates. U.S. Pat. No. 3,901,241.

Pharmaceuticals have also been developed for reducing the size of theturbinates. However, pharmaceuticals are not always completelyefficacious and generally do not provide a permanent reduction inturbinate size. In addition, pharmaceuticals can have adverse sideeffects.

A need exists for a method and device for clearing obstructed nasalpassageways. It is preferred that the method and device be performablewith minimal surgical intervention or post operative complications. Itis also preferred that the method and device be performable to reducethe size of the turbinates without involving surgical cutting or thephysical removal of tissue. It is also preferred that the method anddevice provide a permanent reduction in turbinate size.

SUMMARY OF THE INVENTION

The present invention relates to a method and apparatus for ablating atleast a portion of a nasal concha. In one embodiment, the apparatusincludes a catheter having a distal portion with a dimension configuredfor positioning through a nostril of a patient into a nasal meatusadjacent a nasal concha, and an energy delivery device coupled to thecatheter distal portion including one or more energy delivering probesextendable from the catheter distal portion a sufficient distance to beinserted into an interior of the nasal concha to deliver ablative energytherein.

In another embodiment, the apparatus includes a catheter having a distalportion with a dimension configured for positioning through a nostril ofa patient into a nasal meatus adjacent a nasal concha, the distalportion including an expandable member, expansion of the expandablemember within the nasal meatus immobilizing the distal portion withinthe nasal meatus, and an energy delivery device coupled to the catheterdistal portion including one or more energy delivering probes extendablefrom the catheter distal portion a sufficient distance to be insertedinto an interior of the nasal concha to deliver ablative energy therein.

In this embodiment, the expandable member may be designed to conform toa surface of the nasal concha when expanded and/or to a contour of thenasal meatus. In this embodiment, the apparatus may further include alumen positioned within the catheter for delivering a medium into theexpandable member to expand the expandable member and a medium sourcefor delivering the medium through the lumen into the expandable member.

In another embodiment, the apparatus includes a catheter having a distalportion with a dimension configured for positioning through a nostril ofa patient into a nasal meatus adjacent a surface of a nasal concha, anenergy delivery device coupled to the catheter distal portion includingone or more energy delivering probes extendable from the catheter distalportion a sufficient distance to be inserted into an interior of thenasal concha to deliver ablative energy therein, and an expandablemember coupled to the distal portion having a cooling surface, expansionof the expandable member within the nasal meatus placing the coolingsurface into contact with a surface of the nasal concha to cool thenasal concha surface.

In this embodiment, the cooling surface preferably provides sufficientcooling to prevent the ablation of the nasal concha surface. Theapparatus may further include a lumen positioned within the catheter fordelivering a medium into the expandable member to expand the expandablemember adjacent the surface of the nasal concha and a medium source fordelivering medium of a sufficiently low temperature to cool the surfaceof the nasal concha. Expansion of the expandable member may also be usedto immobilize the catheter distal end within the nasal meatus. In thisembodiment, the expandable member may be designed to conform to asurface of the nasal concha when expanded and/or to a contour of thenasal meatus.

In any of the above embodiments, the one or more energy deliveringprobes may extend a fixed or variable distance from the catheter distalportion. The one or more energy delivering probes are preferablyretractable into the catheter distal portion and extendable from thecatheter distal portion. At least two energy delivering probes arepreferably included in the energy delivery device. An insulator may beused in combination with the probes to control where energy isdelivered. In one variation, the insulator is movable relative to theone or more energy delivering probes.

In any of the above embodiments, the energy delivering probes areadapted to deliver one of a variety of forms of ablative energyincluding, for example, RF, microwave, ultrasonic, pulsed laser anddiffuse laser energy. When delivering RF energy, the probes arepreferably needle electrodes. When delivering laser energy, the probesare preferably optical fibers. When delivering microwave energy, theprobes preferably include microwave antenna. When delivering ultrasonicenergy, the probes preferably include ultrasound transducers.

In any of the above embodiments, the apparatus may further include atleast one sensor coupled to the processor. The sensor may be used tomeasure a variety of properties, including an amount of energy deliveredby the energy delivery device, an amount of heat generated at alocation, an amount of impedance generated, and a temperature at alocation. The energy delivered to the energy delivery device may also becontrolled by the processor in response to a measured property.

In any of the above embodiments, the apparatus may further include anenergy source coupled to the energy delivery device for deliveringenergy to the probes.

A method is also provided for ablating at least a portion of a nasalconcha using a catheter having a distal portion with a dimensionconfigured for positioning through a nostril of a patient into a nasalmeatus adjacent a nasal concha and an energy delivery device coupled tothe catheter distal portion including one or more energy deliveringprobes. In the method, the distal portion of the catheter is positionedthrough a nostril of a patient into a nasal meatus adjacent a surface ofa nasal concha. The one or more energy delivering probes are thenintroduced into an interior of the nasal concha. Sufficient ablativeenergy is then delivered into the interior of the nasal concha to ablateat least a portion of the nasal concha. In the method, the nasal conchais preferably the inferior nasal concha and the nasal meatus ispreferably the inferior nasal meatus. The portion of the nasal conchaablated is preferably an anterior section of the inferior nasal concha.More preferably, less than one-third of the inferior nasal concha in theanterior portion of the inferior nasal concha is ablated. The nasalconcha is preferably reduced in size a sufficient amount to increase therate of airflow through the nasal meatus at a given pressure by at least25%.

According to the method, ablation of the nasal concha is preferably donewithout ablating the surface of the nasal concha. Prevention of thesurface tissue of the nasal concha from being ablated can be performedby the step of cooling the surface of the nasal concha during thedelivery of energy.

In one variation of this method, the catheter includes an expandablemember coupled to the catheter distal portion. According to thisvariation, the method further includes the step of expanding theexpandable member within the nasal meatus to immobilize the distalportion within the nasal meatus. Expansion of the expandable member maybe performed by delivering a medium into the expandable member which maybe delivered through a lumen within the catheter into the expandablemember. This medium may also be used in the method to cool the surfaceof the nasal concha during the delivery of energy in order to preventthe surface of the nasal concha from being ablating.

By using the energy delivering probes, delivery of ablative energy canbe performed substantially bloodlessly. In addition, by allowing theablated tissue to be removed by natural absorption, the step of removingthe ablated nasal concha tissue is performed substantially bloodlesslyand without introducing an element into the nasal concha.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the construction of the nasal passageways of thehuman nose.

FIG. 2 illustrates the effect enlargement of a nasal concha has on anasal air passageway.

FIGS. 3A-3C illustrate an embodiment of a method for ablating a nasalconcha.

FIG. 3A illustrates the introduction of an apparatus through a nostrilinto a nasal meatus adjacent a surface of a nasal concha.

FIG. 3B illustrates the extension of an energy delivery device from theapparatus into an interior of the nasal concha and the delivery ofenergy into the nasal concha.

FIG. 3C illustrates the immobilization of the apparatus within the nasalmeatus and the cooling of the surface of the nasal concha during thedelivery of energy to the nasal concha.

FIGS. 4A-C illustrate the steps of ablating a portion of a nasal conchaaccording to the present invention.

FIG. 4A illustrates the step of introducing ablative energy into aninterior section of a nasal concha.

FIG. 4B illustrates an ablated tissue region and its absorption by thebody.

FIG. 4C illustrates the resulting reduction in the size of the nasalconcha.

FIG. 5 illustrates an apparatus according to the present invention.

FIG. 6 illustrates an apparatus according to the present invention withan expandable member for immobilizing the apparatus within a nasalmeatus.

FIG. 7 is a block diagram of a feedback control system useful with themethod and apparatus of the present invention.

FIG. 8 is a block diagram illustrating an analog amplifier, analogmultiplexer and microprocessor used with the feedback control system ofFIG. 7.

FIG. 9 is a block diagram of a temperature/impedance feedback systemthat can be used to control cooling medium flow rate through anapparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a method and apparatus for ablating atleast a portion of a nasal concha (turbinate). By ablating at least aportion of a nasal concha, the size of the nasal concha can be reduced.Accordingly, the present invention also provides a method for reducingthe size of a nasal concha. The three nasal concha in the body(inferior, middle and superior nasal concha) form at least a portion ofthree nasal meatus (inferior, middle and superior nasal meatus). Byreducing the size of a nasal concha, obstruction of a nasal meatus canbe reduced. By reducing an obstruction of a nasal meatus, air flowthrough the nasal meatus is improved. Accordingly, the present inventionalso relates to a method for improving airflow through a nasal meatus ofthe body.

FIG. 1 illustrates the construction of the nasal passageways of thehuman nose 100. As illustrated in the figure, the human nose includes anostril 102 which leads into the nasal passageways from outside the bodyand a nasopharyngeal opening 104 which leads into the nasal passagewaysfrom the pharynx 106. Connecting the nostril 102 and nasopharyngealopening 104 are a series of passageways, namely the inferior nasalmeatus 108, the middle nasal meatus 110, and the superior nasal meatus112. Forming at least a portion of each of these passageways are thenasal concha, also referred to as the turbinates. Forming at least aportion of the inferior nasal meatus 108 is the inferior nasal concha114. Forming at least a portion of the middle nasal meatus 110 is theinferior nasal concha 114 and the middle nasal concha 116. Forming atleast a portion of the superior nasal meatus 112 is the middle nasalconcha 116 and the superior nasal concha 118. As also shown in FIG. 1,the inferior nasal concha 114 includes an anterior portion 120 whichterminates adjacent the nasopharyngeal opening 104 and a posteriorportion 122 which terminates adjacent the nostril 102.

Ablation of a nasal concha is accomplished according to the presentinvention by physically introducing an energy delivery device into aninterior section of nasal concha tissue to deliver ablative energytherein. In the method and apparatus, the energy delivery device isdesigned to be minimally invasive such that the energy delivery deviceis introduced into the nasal concha without significantly injuring thesurface of the nasal concha (aside from where the energy delivery deviceenters the nasal concha). For example, narrow bore needle-shaped probesfor delivering energy may be used in the energy delivery device forinsertion into the nasal concha.

The use of energy delivered by a minimally invasive means to ablateinterior nasal concha tissue eliminates the need for surgical cutting toremove a portion of a nasal concha and the risks associated therewith.In particular, the procedure can be performed substantially bloodlesslyand without having to expose tissue interior to the nasal concha,thereby significantly reducing the risk of infection.

Ablation can also be performed to remove an internal portion of thenasal concha without injuring the surface of the nasal concha (asidefrom where the energy delivery device enters the nasal concha). Forexample, by inserting the energy delivery device into the interior ofthe nasal concha and delivering energy to the nasal concha away from thesurface of the nasal concha, interior tissue of the nasal concha can beablated without simultaneously ablating the surface of the nasal concha.Cooling of the surface of the nasal concha may also be performed toprevent ablation of the surface of the nasal concha. As a result, thepresent invention provides a method and apparatus for reducing the sizeof a nasal concha without significantly injuring the surface of thenasal concha. By avoiding injury to the surface of the nasal concha, useof the apparatus of the present invention should be significantly lesspainful to the patient than traditional surgical methods for removingnasal concha tissue.

According to the present invention, it is preferred to ablate theinferior nasal concha 114, and more preferably an anterior portion 120of the inferior nasal concha 114. In a preferred embodiment, theanterior portion 120 of the inferior nasal concha 114 is defined asbeing no larger than about one-third the volume of the inferior nasalconcha 114. Thus, in one embodiment, the method includes ablating nomore than about one-third of the inferior nasal concha 114.

FIG. 2 illustrates the effect enlargement of a nasal concha has on anasal air passageway. As shown in FIG. 2, enlargement of the inferiornasal concha 114 can result in an obstruction of inferior nasal meatus108. By reducing the size of the inferior nasal concha 114, illustratedin FIG. 2 by region below dashed line 123, the inferior nasal meatus 108is reopened.

I. Method For Turbinate Ablation

One aspect of the present invention relates to a method for ablatingnasal concha tissue. FIGS. 3A-3C illustrate an embodiment of thismethod. As shown in FIG. 3A, an apparatus 124 having a distal portion128 and an energy delivery device 134 for delivering ablative energy isintroduced through a nostril 102 of a patient and into a nasal meatusadjacent a surface of a nasal concha, shown in FIGS. 3A-3C as theinferior nasal meatus 108 and the inferior nasal concha 114.

The energy delivery device 134 shown in the figures includes threeprobes 139 for delivering ablative energy. These probes are preferablycontained within the distal portion 128 of the apparatus duringintroduction into the nasal meatus and are extended from the distalportion 128 after introduction.

As illustrated in FIG. 3B, the probes 139 are delivered through thesurface 115 of the nasal concha 114 and into an interior section of thenasal concha. The apparatus may be designed such that the probes of theenergy delivery device 134 extend a fixed length from the apparatus.Alternatively, as illustrated in FIG. 3B by arrow (⃡), the energydelivery device 134 may be designed to be at least partially extendablefrom the distal portion 128 and/or at least partially retractable intothe distal portion 128.

Once the probes 139 of the energy delivery device 134 are positionedwithin the nasal concha, ablative energy 117 is delivered through theapparatus and the energy delivery device 134 to an area 119 of the nasalconcha 114 adjacent the probes 139. Sufficient energy 117 is deliveredduring this step to ablate at least a portion of the nasal concha 114.

According to this method, the ablative energy may be any form of energycapable of causing the ablation of tissue by heating at least a portionof the nasal concha being treated to a temperature above about 40° C.Examples of types of energy that may be used include, but are notlimited to energy from a diode laser ablation, a laser fiber (defused),microwave (915 MHz and 2.45 GHz), ultrasound, and RF at all relevantfrequencies. In a preferred embodiment, the energy is electromagneticenergy and is preferably RF radiation or microwave radiation.Illustrated in FIG. 3B are a series of RF electrodes 139 as the energydelivery device 134. The invention is also intended to encompass the useof probes designed to deliver different forms of energy.

When the energy used is RF radiation, the energy preferably has afrequency between about 300 megahertz and about 700 megahertz. The RFenergy delivered to the nasal concha is preferably sufficient to deliverbetween about 5 and about 30 watts of RF energy to at least a portion ofthe nasal concha being treated.

The apparatus of the present invention may be designed to be immobilizedwithin the nasal meatus. This may be accomplished, for example, byincluding an expandable member on the apparatus distal portion 128,illustrated in FIG. 3C and FIG. 6 as element 132.

When expanded within the nasal meatus 108, the expandable member 132serves to immobilize the apparatus distal portion 128 relative to thenasal concha 114 to be ablated. Accordingly, the method may optionallyfurther include the step of immobilizing the apparatus distal portionrelative to the nasal concha. Further, when the apparatus includes anexpandable member, the step of immobilizing the apparatus within thenasal meatus may include the step of expanding the expandable memberwithin the nasal meatus.

The surface 115 of the nasal concha 114 may also be cooled during thedelivery of energy 117. Cooling the surface 115 of the nasal concha 114may be accomplished, for example, by cooling the distal portion 128 ofthe apparatus within the nasal meatus. As illustrated in FIG. 3C, theapparatus may include an expandable member 132 attached to the apparatusat the distal portion 128. In this embodiment, the apparatus alsoincludes a lumen 136 coupled to the apparatus for delivering a medium138 through apertures 137 in the lumen 136 to expand the expandablemember 132. The medium is delivered from a media source 159 through thelumen 136 to within the expandable member 132. During ablation, coolmedia may be delivered from the media source 159 into the expandablemember to cool the surface 115 of the nasal concha.

Cooling the surface of the nasal concha being treated with energy servesat least two purposes. Cooling may be used to prevent ablation of thesurface 115 of the nasal concha 114 by preventing the surface 115 fromreaching a temperature at which the tissue becomes ablated. In thisregard, it is preferred that the cooling be sufficient to prevent thesurface tissue of the nasal concha from exceeding a temperature of about40° C.

Cooling may also be used to control the location of the ablation site.For example, cooling the nasal concha surface enables the formation ofan entirely internal ablation site. The extent of cooling provided, incombination with the positioning of the energy delivery device 134 andthe amount of energy delivered, can be used to control the thickness ofnon-ablated tissue between the surface of the nasal concha and theinternal ablation site.

According to the method, the nasal meatus into which the apparatus isdelivered may be the inferior, middle and/or superior nasal meatus andis preferably the inferior nasal meatus. The nasal concha ablated may bethe inferior, middle and/or superior nasal concha and is preferably theinferior nasal concha. In one embodiment, energy is delivered to aselected section of one of the nasal concha. For example, energy may beselectively delivered to the anterior or posterior sections of theinferior nasal concha. Delivery of energy to a selected section of anasal concha may be accomplished by the placement of the apparatuswithin the nasal meatus. The delivery of energy to a selected section ofa nasal concha may also be accomplished by insulating at least a portionof the nasal concha from ablative energy.

As also illustrated in FIG. 3C, an insulative covering 142 may bepositioned over a portion of the energy delivery device 134 to controlthe delivery of energy to a selected section of tissue. The positioningof the insulative covering 142 may be adjustable relative to the energydelivery device 134. Accordingly, the method may optionally include thefurther step of delivering energy to a portion of a nasal concha whileinsulating another portion of the nasal concha. The method may alsooptionally include the step of adjusting the position of the insulatingcovering 142 relative to the energy delivery device 134.

The present invention also relates to a method for reducing the size ofa nasal concha. According to the method, the size of a nasal concha isreduced by ablating tissue forming a nasal concha and removing theablated nasal concha tissue. Removal of the ablated nasal concha tissueis preferably accomplished by natural absorption of ablated tissue bythe patient's body.

FIGS. 4A-C illustrate the removal of an internal region of tissue byablation. FIG. 4A illustrates introducing ablative energy 117 via energydelivery device probes 139 into an interior section 144 of a nasalconcha 114. Cooling of the surface 115 of the nasal concha 114 may beperformed in order to prevent the ablation of the surface of the nasalconcha.

FIG. 4B illustrates the absorption (illustrated by arrows 148) of aregion 146 of ablated tissue by the body. As illustrated in FIG. 4B, theablated tissue region 146 is an interior region, i.e., the surface 115of the nasal concha is not ablated. This may be achieved by cooling thesurface 115 of the nasal concha during the delivery of ablative energyto the nasal concha. It may also be achieved by controlling thepositioning of the energy delivery device 134 relative to the surface115 and by controlling the amount of energy delivered by the energydelivery device 134.

FIG. 4C illustrates the resulting reduction in the size of the nasalconcha after absorption. Region 149 illustrates the volume of tissuethat is removed from the path of the nasal meatus by this method. As canbe seen by comparing FIGS. 4A and 4C, the size of nasal meatus 108 isenlarged by this process.

The present invention also relates to a method for improving airflowthrough a nasal meatus by reducing the size of a nasal concha whichdefines at least a portion of the nasal meatus. This method can beaccomplished by the method for reducing the size of a nasal concha asdescribed above. In one embodiment, the rate of airflow through thenasal meatus at a given pressure is increased by at least 25%.

2. Turbinate Ablation Apparatus

The present invention also relates to an apparatus for ablating a nasalconcha. As illustrated in FIG. 5, the apparatus 124 includes a catheter126 which has a distal portion 128 with dimensions configured forintroduction through a nostril of a patient into a nasal meatus of apatient.

The apparatus also includes an energy delivery device 134. The energydelivery device 134 is illustrated in the figure as including aplurality of probes 139 designed to pierce the nasal concha and deliverablative energy therein. In order to facilitate the entry of the probesinto the nasal concha, each probe preferably includes a pointed distalend 135.

The probes 139 of the energy delivery device 134 may extend a fixeddistance from the catheter distal portion 128. In such case, the probes139 should extend from the catheter distal portion 128 a sufficientdistance necessary to ablate an interior portion of the nasal concha114. Alternatively, as illustrated in FIG. 5 by the arrow (⃡), the energydelivery device 134 may be designed to be at least partially extendablefrom the catheter distal portion 128 and/or at least partiallyretractable into the catheter distal portion 128.

The energy delivery device 134 should also be configured to selectivelyintroduce the probes into the nasal concha or a selected subregion ofthe nasal concha. Accordingly, when a plurality of probes 139 are usedas illustrated in FIG. 5, the probes should be positioned relative tothe catheter distal portion 128 so that the probes 139 are allintroduced into the nasal concha and not into other tissue adjacent thenasal concha.

The probes 139 used in the energy delivery device 134 may be any probewhich can pierce the surface of a nasal concha and which can deliver aform of energy capable of causing the ablation of tissue. Ablation ispreferably performed by heating at least a portion of the nasal conchato be treated to a temperature above about 40° C. Examples of types ofenergy that may be used include, but are not limited to energy from adiode laser ablation, a laser fiber (defused), microwave (915 MHz and2.45 GHz), ultrasound, and RF at all relevant frequencies. In apreferred embodiment, the energy is electromagnetic energy and ispreferably RF radiation or microwave radiation delivered into the nasalconcha by one or more needle electrodes.

When the energy is RF radiation, the energy preferably has a frequencybetween about 300 megahertz and about 700 megahertz. The RF energydelivered to the nasal concha is preferably sufficient to deliverbetween about 5 and about 30 watts of RF energy to at least a portion ofthe nasal concha being treated.

As illustrated in FIG. 5, the energy delivery device may optionallyinclude an insulator 162 surrounding each probe 139 which prevents thedelivery of ablative energy 117 through at least a portion of the probe139. As illustrated in FIG. 5, by the dashed lines 161, the insulator162 may be moved relative to the energy delivery device 134 to causeenergy to be delivered to a selected section of a nasal concha whilepreventing the ablation of another selected section of tissue.

As illustrated in FIG. 6, an expandable member 132 may be attached tothe catheter 126 at the catheter distal portion 128. The expandablemember can be used to immobilize the catheter distal portion 128 withinthe nasal meatus by expanding against the walls forming the nasalmeatus. The expandable member preferably conforms to a contour of thenasal meatus when expanded. In one embodiment, the expandable memberconforms to the surface of the nasal concha when expanded.

A variety of mechanisms are known in the art which may be used to expandthe expandable member 132. One mechanism, illustrated in FIG. 6,involves the use of a lumen 136 coupled with the catheter 126 fordelivering a medium 138 to expand the expandable member 132. The mediumis delivered from a media source 159 through the lumen 136 to within theexpandable member 132 through apertures 137. The apertures 137 may beformed by a sheath 150 which substantially surrounds the lumen 136. Inone embodiment, the sheath 150 is formed of a relatively inert andrelatively hard substance, such as metallic copper or metallic silver.In alternative embodiments, the sheath 150 includes some other inertsubstance, such as gold, stainless steel, titanium, various plasticcompounds, or some combination thereof.

The expandable member illustrated in FIG. 6 can also be used to cool thesurface of a nasal concha being ablated. Cooling may be accomplished byintroducing cool medium into the expandable member. This may beaccomplished, for example, by including a cooling mechanism into themedia source 159 to cool the media.

As illustrated in FIG. 5, ablative energy is supplied to the energydelivery device by an energy source 162. As discussed above, a varietyof forms of ablative energy may be used in the present invention.Accordingly, the energy source is selected to provide the desired formof energy.

In one embodiment, the energy source 162 includes an energy source 163(or a power regulator coupled to a standard energy source such as a wallsocket or battery), a signal generator 165 (such as a generator forpulses, sine waves, square waves, or some combination of these waveforms with each other or with some other wave form), and a processor 167for controlling the signal generator.

In a preferred embodiment, the signal generator generates pulses of RFenergy having an RF radiation frequency between about 300 megahertz andabout 700 megahertz, such as preferably about 465 megahertz. Inalternative embodiments, the RF energy may have an RF radiationfrequency in the microwave range or in another range of theelectromagnetic spectrum.

The processor controls the amount of energy delivered by the apparatus.In this embodiment, the apparatus can further include a signal generatorcoupled to the energy delivery device and coupled to a energy source.The apparatus can also include a processor coupled to the signalgenerator and disposed for controlling the signal generator. Accordingto this embodiment, the processor can control the way in which energy isdelivered. For example, the signal generator can generate pulses of RFenergy which provide between about 5 watts and about 30 watts of RFenergy to at least a portion of the turbinate. The processor can alsocontrol the amount of energy produced so that the region of turbinatetissue to be ablated is heated to a temperature of at least 40° C.

In order to monitor the amount of energy delivered and the amount ofheat generated, the apparatus can also include one or more sensors.These sensors can be used to detect a variety of operating parametersincluding the amount of energy delivered, the impedance generated, andthe temperature of a region adjacent the apparatus. These sensors canalso be used to provide feedback for controlling the operation of anenergy source which delivers energy to the energy delivery device. Inaddition, chemical or biochemical sensors can be used to detectablation.

In one embodiment, the apparatus includes at least one temperaturesensor, such as a thermocouple or thermistor. The temperature sensor iscoupled to a communication link (such as a conductor), which is coupledto the processor. For example, in the case where the temperature sensoris a thermocouple, the communication link may comprise a D/A convertercoupled to a register disposed for reading by the processor. Theprocessor reads an sensor value from the sensor and, responsive thereto,controls the signal generator so as to achieve delivery of an effectiveamount of RF energy to a desired section of tissue to be ablated. Theprocessor thus uses the signal generator, catheter distal portion,energy delivery device, and temperature sensor, as a feedback loop forcontrolled delivery of RF energy to a section of a nasal concha. Forexample, the processor may control the delivery of RF energy to achievedelivery of a selected amount of energy, to achieve a selectedtemperature, or to achieve a selected amount of ablation of a section ofa nasal concha. A variety of positionings for the sensors are possible.In one embodiment, the sensor is coupled to the expandable member.

As described above, the temperature or some other property of the tissuebeing ablated, or of the energy delivery device can be monitored using avariety of sensors. Illustrated in FIGS. 7 and 8 is an open and a closedloop feedback system for coupling a sensor used in the apparatus to anenergy source so that the output energy of the energy source is adjustedin relation to the property sensed by the sensor. The feedback system,is described herein with regard to the delivery of RF energy. It shouldbe noted, however, that the feedback system can be readily adjusted foruse with a variety of other types of energy, such as microwaves.

Using the feedback system, the physician can, if desired, override theclosed or open loop system. A microprocessor can be included andincorporated in the closed or open loop system to switch energy on andoff, as well as modulate the energy. The closed loop system utilizes amicroprocessor to serve as a controller, watch the temperature, adjustthe amount of energy being delivered, look at the result, re-feed theresult, and then modulate the energy.

In the case of RF energy, the sensors and feedback control system can beused to, maintained tissue adjacent to an energy delivery device at adesired temperature for a selected period of time without impeding out.An output maintains the energy delivered to the energy delivery devicefor a selected length of time.

As illustrated in FIG. 7, current is delivered through energy deliverydevice 189 is measured by current sensor 190. Voltage is measured byvoltage sensor 192. Impedance and energy are then calculated at energyand impedance calculation device 194. These values can then be displayedat a user interface and display 196. Signals representative of energyand impedance values are received by a controller 198.

A control signal is generated by controller 198 that is proportional tothe difference between an actual measured value, and a desired value.The control signal is used by energy circuits 200 to adjust the energyoutput in an appropriate amount in order to maintain the desired energydelivered at each energy delivery device 189.

In a similar manner, temperatures detected at temperature sensors 191provide feedback for maintaining a selected energy. The actualtemperatures are measured at temperature measurement device 202, and thetemperatures are displayed at user interface and display 196. A controlsignal is generated by controller 198 that is proportional to thedifference between an actual measured temperature, and a desiredtemperature. The control signal is used by energy circuits 200 to adjustthe energy output in an appropriate amount in order to maintain thedesired temperature delivered at the respective sensor. A multiplexercan be included to measure current, voltage and temperature, at numeroussensors, and energy can be delivered to the energy delivery device 189in monopolar or bipolar fashion.

Controller 198 can be a digital or analog controller, or a computer withsoftware. When controller 198 is a computer it can include a CPU coupledthrough a system bus. On this system can be a keyboard, a disk drive, orother non-volatile memory systems, a display, and other peripherals, asare known in the art. Also coupled to the bus is a program memory and adata memory.

User interface and display 196 includes operator controls and a display.Controller 198 can be coupled to imaging systems, including but notlimited to ultrasound, CT scanners, X-ray, MRI, mammographic X-ray andthe like. Further, direct visualization and tactile imaging can beutilized.

The output of current sensor 190 and voltage sensor 192 is used bycontroller 198 to maintain a selected energy level at energy deliverydevice 189. The amount of energy delivered controls the amount ofenergy. A profile of energy delivered can be incorporated in controller198, and a preset amount of energy to be delivered can also be profiled.

Circuitry, software and feedback to controller 198 result in processcontrol, and the maintenance of the selected energy that is independentof changes in voltage or current, and are used to change, (i) theselected energy, (ii) the duty cycle (on-off and wattage), (iii) bipolaror monopolar energy delivery, and (iv) infusion medium delivery,including flow rate and pressure. These process variables are controlledand varied, while maintaining the desired delivery of energy independentof changes in voltage or current, based on temperatures monitored atsensors 191.

Current sensor 190 and voltage sensor 192 are connected to the input ofan analog amplifier 204. Analog amplifier 204 can be a conventionaldifferential amplifier circuit for use with temperature sensors 191. Theoutput of analog amplifier 204 is sequentially connected by an analogmultiplexer 206 to the input of AND converter 208. The output of analogamplifier 204 is a voltage which represents the respective sensedtemperatures. Digitized amplifier output voltages are supplied by A/Dconverter 208 to microprocessor 188. Microprocessor 188 may be a type68HCII available from Motorola. However, it will be appreciated that anysuitable microprocessor or general purpose digital or analog computercan be used to calculate impedance or temperature.

Microprocessor 188 sequentially receives and stores digitalrepresentations of impedance and temperature. Each digital valuereceived by microprocessor 188 corresponds to different temperatures andimpedances.

Calculated energy and impedance values can be indicated on userinterface and display 196. Alternatively, or in addition to thenumerical indication of energy or impedance, calculated impedance andenergy values can be compared by microprocessor 188 with energy andimpedance limits. When the values exceed predetermined energy orimpedance values, a warning can be given on user interface and display196, and additionally, the delivery of RF energy can be reduced,modified or interrupted. A control signal from microprocessor 188 canmodify the energy level supplied by energy source 203

FIG. 9 illustrates a block diagram of a temperature/impedance feedbacksystem that can be used to control cooling medium flow rate through thecatheter into the expandable member. Ablative energy is delivered toenergy delivery device 189 by energy source 203, and applied to tissue.A monitor 210 ascertains tissue impedance, based on the energy deliveredto tissue, and compares the measured impedance value to a set value. Ifthe measured impedance exceeds the set value a disabling signal 211 istransmitted to energy source 203, ceasing further delivery of energy tothe energy delivery device 189. If measured impedance is withinacceptable limits, energy continues to be applied to the tissue. Duringthe application of energy to tissue sensor 191 measures the temperatureof tissue and/or energy delivery device 189. A comparator 214 receives asignal representative of the measured temperature and compares thisvalue to a pre-set signal representative of the desired temperature.Comparator 214 sends a signal to a flow regulator 216 representing aneed for a higher cooling medium flow rate, if the tissue temperature istoo high, or to maintain the flow rate if the temperature has notexceeded the desired temperature.

While the present invention is disclosed by reference to the preferredembodiments and examples detailed above, it is to be understood thatthese examples are intended in an illustrative rather than limitingsense, as it is contemplated that modifications will readily occur tothose skilled in the art, which modifications will be within the spiritof the invention and the scope of the appended claims.

What is claimed is:
 1. An apparatus for ablating at least a portion of anasal concha comprising:a catheter having a distal portion with a lengthoperable for positioning through a nostril of a patient into a nasalmeatus adjacent a nasal concha, the catheter further including acatheter longitudinal axis and a catheter side wall; and an energydelivery device coupled to the catheter distal portion including one ormore energy delivering probes extendable from the catheter distalportion a sufficient distance to be inserted into an interior of thenasal concha to deliver ablative energy therein, wherein the one or moreenergy delivering probes are extendable from the catheter side wall in alateral direction relative to the catheter longitudinal axis.
 2. Theapparatus according to claim 1 wherein the one or more energy deliveringprobes extend a fixed distance from the catheter distal portion.
 3. Theapparatus according to claim 1 wherein the distance the one or moreenergy delivering probes extend from the catheter distal portion can bevaried.
 4. The apparatus according to claim 1 wherein the one or moreenergy delivering probes are retractable into the catheter distalportion and extendable from the catheter distal portion.
 5. Theapparatus according to claim 1 wherein the energy delivery deviceincludes at least two energy delivering probes.
 6. The apparatusaccording to claim 1 wherein the one or more energy delivering probesdeliver energy selected from the group consisting of RF, microwave,ultrasonic, pulsed laser and diffuse laser energy.
 7. The apparatusaccording to claim 1 wherein the one or more energy delivering probesare needle electrodes for delivering RF energy.
 8. The apparatusaccording to claim 1 wherein the one or more energy delivering probesinclude an optical fiber for delivering laser energy.
 9. The apparatusaccording to claim 1 wherein the one or more energy delivering probesare antenna for delivering microwave energy.
 10. The apparatus accordingto claim 1 wherein the one or more energy delivering probes includetransducers for delivering ultrasonic energy.
 11. The apparatusaccording to claim 1 wherein the apparatus further includes an insulatorpositioned adjacent at least a portion of the one or more energydelivering probes to prevent the delivery of energy therethrough. 12.The apparatus according to claim 11 wherein the insulator is movablerelative to the one or more energy delivering probes.
 13. The apparatusaccording to claim 1 wherein the apparatus includes a signal generatorcoupleable to an energy source for generating pulses of electromagneticenergy having a frequency between about 300 and 700 megahertz.
 14. Theapparatus according to claim 13, wherein the apparatus further includesa processor coupled to the signal generator for generating pulses of RFenergy which provide between about 5 and about 30 watts of RF energy.15. The apparatus according to claim 14, wherein the apparatus furtherincludes at least one sensor coupled to the processor.
 16. The apparatusaccording to claim 15, wherein the sensor measures a property selectedfrom the group consisting of an amount of energy delivered by the energydelivery device, an amount of heat generated at a location, an amount ofimpedance generated, and a temperature at a location.
 17. The apparatusaccording to claim 14, wherein the energy delivered to the energydelivery device is controlled by the processor in response to a measuredproperty selected from the group consisting of an amount of energydelivered by the energy delivery device, an amount of heat generated ata location, an amount of impedance generated, and a temperature at alocation.
 18. The apparatus according to claim 17, wherein the apparatusincludes a sensor for measuring the measured property.
 19. An apparatusfor ablating at least a portion of a nasal concha comprising:a catheterhaving a distal portion with a length operable for positioning through anostril of a patient into a nasal meatus adjacent a nasal concha, thecatheter further including a catheter longitudinal axis and a catheterside wall; an energy delivery device coupled to the catheter distalportion including one or more energy delivering probes extendable fromthe catheter distal portion a sufficient distance to be inserted into aninterior of the nasal concha to deliver ablative energy therein, whereinthe one or more energy delivering probes are extendable from thecatheter side wall in a lateral direction relative to the catheterlongitudinal axis; and an energy source coupled to the energy deliverydevice for delivering energy to the probes.
 20. The apparatus accordingto claim 19 wherein the energy source delivers energy to the one or moreenergy delivering probes selected from the group consisting of RF,microwave, ultrasonic, pulsed laser and diffuses laser energy.
 21. Theapparatus according to claim 20 wherein the one or more energydelivering probes are needle electrodes for delivering RF energy. 22.The apparatus according to claim 20 wherein the one or more energydelivering probes include an optical fiber for delivering laser energy.23. The apparatus according to claim 20 wherein the one or more energydelivering probes are antenna for delivering microwave energy.
 24. Theapparatus according to claim 20 wherein the one or more energydelivering probes include transducers for delivering ultrasonic energy.25. The apparatus according to claim 20 wherein the apparatus includes asignal generator coupled to the energy source for generating pulses ofelectromagnetic energy having a frequency between about 300 and 700megahertz.
 26. The apparatus according to claim 25, wherein theapparatus further includes a processor coupled to the signal generatorfor generating pulses of RF energy which provide between about 5 andabout 30 watts of RF energy.